For example, in a manufacturing process for forming a circuit pattern on a material, such as a glass substrate for a liquid crystal, a semiconductor wafer, etc., it is required that various kinds of processing be performed on the material and it is required that, as one such processing, the material be washed to a high purity level.
In the washing of a material to be washed, various kinds of washing means (processing sections) are known, such as an ultraviolet ray irradiation means for irradiating the material with the ultraviolet ray and decomposing an organic matter for removal, a brush washing means for washing a material which is conveyed with a brush, while applying a chemical solution, etc., to the conveyed material, and a spin washing means for applying a washing solution, such as a chemical solution, to a material while being spun with the material retained on a table. In the case where the washing processing is done on the material with the use of a plurality of washing means, a conveying means (processing section) is also provided for conveying the material to and from these washing means.
In order to increase the purity level of the material, the material is washed by as many washing means as possible out of the above-mentioned washing means. In this case, it has been normal practices to juxtapose utilized washing means in a plane in a clean room and sequentially convey the washing material to and from a plurality of washing means by conveying means.
If, however, the plurality of washing means and conveying means are arranged in a plane, a greater space was sometimes taken up by the washing means and conveying means in the clean room. It is required that a space be utilized in the clean room as effectively as possible. It is, therefore, desirable to decrease the occupation space of the plurality of washing means and conveying means.
If the above-mentioned material is to be conveyed to and from the juxtaposed washing means, it is only necessary to continuously convey the material by the conveyor in the case where the washing processing can be continuously performed by the washing means. In the case where, however, the washing processing by the washing means cannot be continuously done such as the spin washing, it has been the practice to convey the material by a robot apparatus constituting the above-mentioned conveying means which is one of the processing units.
When the robot apparatus is used as the conveying means, there is sometimes the case where this robot apparatus is run along a plurality of juxtaposed washing means. In this case, a track is provided over a range over which the robot apparatus is run.
There is sometimes the case where, when the convey-in/convey-out of the washing material by the robot apparatus is done, a washing solution drops from the material onto the above-mentioned track. Use is sometimes made, as a washing solution, of, in addition to pure water, a chemical solution of high acidity for instance. For this reason, there was sometimes the case where, if the chemical solution is used as the washing solution, the chemical solution dropping from the material corroded the track and caused an injury to cables for controlling the above-mentioned robot apparatus.
Further, there is sometimes the case where, when the material is conveyed by the robot apparatus to a predetermined washing means, until the washing of the material by the washing means is completed, the material washed at a previous step need be kept in a standby state with the material retained. In this case, when the standby time becomes longer, the washing solution deposited on the material in the previous step dried up and there was sometimes the case where a spot, etc., was formed on the material.
The above-mentioned "space problem" may arise not only in the case where the material is subjected to wash processing but also may arise even in various steps involved. In the case where, for example, a resist is coated on the material, a plurality of processing units has to be provided, such as a coating device, heating device and preheating device, thus producing a similar problem.